diff --git a/lua_obj.lua b/lua_obj.lua
index eca0bf1..569752a 100644
--- a/lua_obj.lua
+++ b/lua_obj.lua
@@ -150,13 +150,17 @@ do
   _class_0 = setmetatable({
     __init = function(self, source, ...)
       self.source = source
-      if type(self.source) == 'string' then
-        local filename, start, stop = self.source:match("^(.-)[(%d+):(%d+)]$")
-        self.source = Source(filename, tonumber(start), tonumber(stop))
-      end
       self.bits = {
         ...
       }
+      if type(self.source) == 'string' then
+        local filename, start, stop = self.source:match("^(.-)[(%d+):(%d+)]$")
+        if start or stop then
+          self.source = Source(filename, tonumber(start), tonumber(stop))
+        else
+          self.source = Source(self.source, 1, #self)
+        end
+      end
     end,
     __base = _base_0,
     __name = "Code"
diff --git a/lua_obj.moon b/lua_obj.moon
index 6ee1970..c315bdc 100644
--- a/lua_obj.moon
+++ b/lua_obj.moon
@@ -62,10 +62,13 @@ Source = immutable {"filename","start","stop"}, {
 
 class Code
     new: (@source, ...)=>
+        @bits = {...}
         if type(@source) == 'string'
             filename,start,stop = @source\match("^(.-)[(%d+):(%d+)]$")
-            @source = Source(filename, tonumber(start), tonumber(stop))
-        @bits = {...}
+            if start or stop
+                @source = Source(filename, tonumber(start), tonumber(stop))
+            else
+                @source = Source(@source, 1, #self)
 
     clone: =>
         cls = @__class
diff --git a/nomsu.lua b/nomsu.lua
index 9a55d6a..6013467 100644
--- a/nomsu.lua
+++ b/nomsu.lua
@@ -61,7 +61,16 @@ local line_counter = re.compile([[    lines <- {| line (%nl line)* |}
 LINE_STARTS = setmetatable({ }, {
   __mode = "k",
   __index = function(self, k)
-    local line_starts = line_counter:match(tostring(k))
+    if type(k) ~= 'string' then
+      k = tostring(k)
+      do
+        local v = rawget(self, k)
+        if v then
+          return v
+        end
+      end
+    end
+    local line_starts = line_counter:match(k)
     self[k] = line_starts
     return line_starts
   end
@@ -203,7 +212,7 @@ end
 local NomsuCompiler
 do
   local _class_0
-  local stub_defs, stub_pattern, var_pattern
+  local _nomsu_chunk_counter, stub_defs, stub_pattern, var_pattern
   local _base_0 = {
     define_action = function(self, signature, source, fn)
       if type(fn) ~= 'function' then
@@ -330,11 +339,14 @@ do
       assert(tree, "In file " .. tostring(colored.blue(filename)) .. " failed to parse:\n" .. tostring(colored.onyellow(colored.black(nomsu_code))))
       return tree
     end,
-    run = function(self, nomsu_code, source)
-      if type(source) == 'string' then
-        source = Source(source, 1, #nomsu_code)
+    run = function(self, nomsu_code)
+      if type(nomsu_code) == 'string' then
+        _nomsu_chunk_counter = _nomsu_chunk_counter + 1
+        local filename = "<nomsu chunk #" .. tostring(_nomsu_chunk_counter) .. ">.nom"
+        nomsu_code = Nomsu(filename, nomsu_code)
+        FILE_CACHE[filename] = nomsu_code
       end
-      if nomsu_code == "" then
+      if #nomsu_code == 0 then
         return nil
       end
       local tree = self:parse(nomsu_code, source)
@@ -367,14 +379,14 @@ do
           local lua_filename = filename:gsub("%.nom$", ".lua")
           local file = FILE_CACHE[lua_filename]
           if file then
-            return self:run_lua(file, lua_filename)
+            return self:run_lua(file)
           end
         end
         local file = file or FILE_CACHE[filename]
         if not file then
           error("File does not exist: " .. tostring(filename), 0)
         end
-        return self:run(file, filename)
+        return self:run(file)
       else
         return error("Invalid filetype for " .. tostring(filename), 0)
       end
@@ -1226,6 +1238,7 @@ do
   })
   _base_0.__class = _class_0
   local self = _class_0
+  _nomsu_chunk_counter = 0
   self.unescape_string = function(self, str)
     return Cs(((P("\\\\") / "\\") + (P("\\\"") / '"') + NOMSU_DEFS.escaped_char + P(1)) ^ 0):match(str)
   end
@@ -1353,7 +1366,7 @@ if arg and debug_getinfo(2).func ~= require then
       else
         local retval, code
         if args.input == '-' then
-          retval, code = nomsu:run(io.read('a'), 'stdin')
+          retval, code = nomsu:run(io.read('a'))
         else
           retval, code = nomsu:run_file(args.input)
         end
@@ -1367,7 +1380,7 @@ if arg and debug_getinfo(2).func ~= require then
       end
     end
     if args.flags["-i"] then
-      nomsu:run('use "core"', "stdin")
+      nomsu:run('use "core"')
       while true do
         io.write(colored.bright(colored.yellow(">> ")))
         local buff = ""
@@ -1384,9 +1397,7 @@ if arg and debug_getinfo(2).func ~= require then
           break
         end
         local ret
-        ok, ret = pcall(function()
-          return nomsu:run(buff, "stdin")
-        end)
+        ok, ret = pcall(nomsu.run, nomsu, buff)
         if ok and ret ~= nil then
           print("= " .. repr(ret))
         elseif not ok then
diff --git a/nomsu.moon b/nomsu.moon
index d9c3252..e10a8c3 100755
--- a/nomsu.moon
+++ b/nomsu.moon
@@ -41,6 +41,7 @@ debug_getinfo = debug.getinfo
 -- Re-implement nomsu-to-lua comment translation
 
 export FILE_CACHE
+-- FILE_CACHE is a map from filename (string) -> file contents (Lua or Nomsu object)
 FILE_CACHE = setmetatable {}, {
     __index: (filename)=>
         file = io.open(filename)
@@ -62,10 +63,16 @@ line_counter = re.compile([[
 ]], nl:P("\r")^-1 * P("\n"))
 -- Mapping from line number -> character offset
 export LINE_STARTS
+-- LINE_STARTS is a mapping from strings to a table that maps line number to character positions
 LINE_STARTS = setmetatable {}, {
     __mode:"k"
     __index: (k)=>
-        line_starts = line_counter\match(tostring(k))
+        -- Implicitly convert Lua and Nomsu objects to strings
+        if type(k) != 'string'
+            k = tostring(k)
+            if v = rawget(self, k)
+                return v
+        line_starts = line_counter\match(k)
         self[k] = line_starts
         return line_starts
 }
@@ -297,10 +304,14 @@ class NomsuCompiler
         assert tree, "In file #{colored.blue filename} failed to parse:\n#{colored.onyellow colored.black nomsu_code}"
         return tree
 
-    run: (nomsu_code, source)=>
-        if type(source) == 'string'
-            source = Source(source,1,#nomsu_code)
-        if nomsu_code == "" then return nil
+    _nomsu_chunk_counter = 0
+    run: (nomsu_code)=>
+        if type(nomsu_code) == 'string'
+            _nomsu_chunk_counter += 1
+            filename = "<nomsu chunk ##{_nomsu_chunk_counter}>.nom"
+            nomsu_code = Nomsu(filename, nomsu_code)
+            FILE_CACHE[filename] = nomsu_code
+        if #nomsu_code == 0 then return nil
         tree = @parse(nomsu_code, source)
         assert tree, "Failed to parse: #{nomsu_code}"
         assert tree.type == "File", "Attempt to run non-file: #{tree.type}"
@@ -328,11 +339,11 @@ class NomsuCompiler
                 lua_filename = filename\gsub("%.nom$", ".lua")
                 file = FILE_CACHE[lua_filename]
                 if file
-                    return @run_lua(file, lua_filename)
+                    return @run_lua(file)
             file = file or FILE_CACHE[filename]
             if not file
                 error("File does not exist: #{filename}", 0)
-            return @run(file, filename)
+            return @run(file)
         else
             error("Invalid filetype for #{filename}", 0)
     
@@ -939,7 +950,7 @@ if arg and debug_getinfo(2).func != require
             else
                 local retval, code
                 if args.input == '-'
-                    retval, code = nomsu\run(io.read('a'), 'stdin')
+                    retval, code = nomsu\run(io.read('a'))
                 else
                     retval, code = nomsu\run_file(args.input)
                 if compiled_output
@@ -951,7 +962,7 @@ if arg and debug_getinfo(2).func != require
 
         if args.flags["-i"]
             -- REPL
-            nomsu\run('use "core"', "stdin")
+            nomsu\run('use "core"')
             while true
                 io.write(colored.bright colored.yellow ">> ")
                 buff = ""
@@ -964,7 +975,7 @@ if arg and debug_getinfo(2).func != require
                     io.write(colored.dim colored.yellow ".. ")
                 if #buff == 0
                     break
-                ok, ret = pcall(-> nomsu\run(buff, "stdin"))
+                ok, ret = pcall(nomsu.run, nomsu, buff)
                 if ok and ret != nil
                     print "= "..repr(ret)
                 elseif not ok